1. Field of the Invention
The present invention relates to a power transfer switch, and more particularly, to a one body-type power transfer switch in which a disconnecting portion is integrally formed to reduce errors arisen due to accumulated assembly tolerance and simplify manufacturing processes, thereby improving operators' convenience.
2. Description of the Related Art
Generally, when power is shut off from a substation to a workplace or building including a self generator, a power transfer switch automatically transfers power from an interior wiring terminal to a self generator to continue to supply power. Then, when power is normally supplied from the substation, the power transfer switch automatically transfers power so that power may be normally supplied from the substation.
The power transfer switch alternatively connects two different power sources, such as a normal power source and an emergency power source, or a star-connection power source and delta-connection power source, to a load side, and has various forms according to the capacity and use thereof.
Korean Utility Model Publication No. 87-1383 disclose a power transfer switch including a manipulation lever, a controlling axis, a movable contactor, a point plate and latch. In addition, the present applicant has invented and applied a power transfer switch that is more advanced than the power transfer switch disclosed in Korean Utility Model Publication No. 1987-0001383, as Patent Application No. 10-1996-0032363 (applied on Aug. 2, 1996).
FIG. 1 is a perspective view of a power transfer switch 1 for family use and for a small capacity. Referring to FIG. 1, the power transfer switch 1 connects or disconnects two different power sources, such as a normal power source and an emergency power source, or a star-connection power source and delta-connection power source. In addition, the power transfer switch 1 includes a disconnecting portion 10 through which phases R, S, T and N are exposed out of the power transfer switch 1, and a driving portion 20 from which a magnetic force is generated so that power may continue to supply power to products requiring power while contacts between the power transfer switch and an interior wiring terminal vary as a substation as a transmitting side is grounded.
That is, in the power transfer switch 1, while the phases R, S, T and N constituting a normal power terminal (not shown), an emergency power terminal 12 and a load terminal 13 are each installed in a separate frame 10′, the phases R, S, T and N are sequentially assembled using bolts and adhesives to constitute a disconnecting portion 10. The driving portion 20 is disposed at one end of the disconnecting portion 10 so as to selectively supply power.
However, in the power transfer switch 1, while the phases R, S, T and N are each installed in the separate frame 10′, the phases R, S, T and N are sequentially assembled using bolts and adhesives. Thus, an error may arise due to current when the power transfer switch 1 operates according to an accumulated assembly tolerance, thereby reducing reliability of the power transfer switch 1.
In addition, the phases R, S, T and N need to be sequentially assembled, it is inconvenient to assembly the power transfer switch 1, and it takes a long time to assemble the power transfer switch 1.